Satz

Framework for JSON microservices

Satz is a framework for writing microservices that serve and read JSON. It uses Syro for routing requests. Check the Syro tutorial to learn more about how the routing works.

An example of a Satz application would look like this:

App = Satz.define do
  on "players" do
    on :player_id do
      get do
        @player = Player[inbox[:player_id]]

        reply @player
      end
    end

    get do
      reply Player.all.to_a
    end

    post do
      @player = Player.new(read)

      on @player.valid? do
        @player.create

        reply @player
      end

      default do
        reply @player.errors
      end
    end
  end
end

The argument to reply is served as JSON by calling JSON.dump(arg). In user defined objects, you can define the method to_json according to your needs. Most ORMs already provide meaningful definitions for that method.

The auth method checks if Basic Auth headers were provided and returns nil otherwise. If it's able to access the supplied credentials, it yield the username and password and returns the result (if it's not false) or nil.

Here's an example of how to use it:

@user = auth do |user, pass|

  # Here you can use any method of your
  # choice. The example is from Shield.
  User.authenticate(user, pass)
end

on @user.nil? do
  res.status = 401
  reply(error: "Unauthorized")
end

Anything defined after that on block will be executed only if the authentication succeded.

The default serializer is JSON, but it can be customized by supplying a serializer:

Satz.serializer = MySerializer

A serializer must respond to load(arg) and dump(arg), and that's the only restriction. Note that the supplied serializer will be used by all Satz applications.

Apart from Syro's API, the following methods are available:

auth: Process Basic Auth headers and yield username and password.

read: Reads the body of the request and parses it as JSON.

reply: Writes to the response its argument encoded as JSON.

$ gem install satz